Achiel Hendrikx

ANALYSIS BY MEANS OF AN ANALOG COMPUTER OF PLASMA CORTICOID VALUES DURING ADRENOCORTICOTROPIC HORMONE INFUSION

Several parameters have been described by Samuels and his collaborators (1-4) to evaluate cortisol metabolism. On the one hand, they utilize the intravenous administration of cortisol or other steroids for calculating the removal rate, the half-time and the apparent distribution volume of the injected substance. On the other hand, by the intravenous infusion of ACTH they obtain a convex curve of plasma concentrations of cortisol when they are plotted against time; they interpret this curve as being the result of two processes occurring simultaneously: a) a constant (maximal) adrenal production rate, and b) a constant removal of corticosteroids in direct proportion to the concentration at a given moment. In order to calculate (maximal) adrenal production of cortisol, Samuels assumes the cortisol removal rate during ACTH infusion to be identical with the removal rate obtained after the intravenous administration of cortisol. This assumption however is at variance with other data from the same author. With the use of labeled cortisol he was able to show that the removal rate is dependent upon the initial cortisol level and that the values obtained with low initial cortisol levels were distinctly higher than the resultant figures after massive cortisol infusion. In the present study ACTH and cortisol infusions were performed. By using an analog computer for analyzing the obtained data, it was possible to test in a direct way the hypotheses proposed by Samuels and associates. This instrument makes it possible to measure simultaneously the two determining constants of a differential equation. The parameters p and r, as used by Samuels (and also in this paper) are relative rates, p being expressed as micrograms per unit volume of blood per hour, r meaning the percentage diminution in concentration relative to the concentration at the beginning of each consecutive time period (see Calculations).

Positional distribution of the fatty acids in the triglycerides of mango (Mangifera indica) kernel fat

Triglycerides of mango seed kernel fat contain, depending on the variety, 32.4–44.0% of stearic acid and 43.7–54.5% of oleic acid. Palmitic and linoleic acids represent, respectively, 5.9–9.1% and 3.6–6.7% of the fatty acids. The triglycerides also contain minor amounts of arachidic and linolenic acids. Palmitic, stearic and arachidic acids were almost exclusively distributed among thesn-1-andsn-3-positions. Oleic acid represented 85–89% of the fatty acids at thesn-2-position. Oleic acid at thesn-1- andsn-3-positions showed a preference for thesn-1-position. Linoleic acid was mainly esterified at thesn-2-position. The amounts of saturated fatty acids, i.e., palmitic and stearic acids, and of oleic acid, at thesn-1- and sn-3-positions, were linearly related to their respective contents in the total triglycerides.

Positional distribution of the fatty acids in the triglycerides of the oil of some african peanut varieties

The distribution of fatty acids between the sn-1-, sn-2- and sn-3-positions of the triglycerides from the oils of eight African peanut varieties has been determined. The saturated fatty acids and eicosenoic acid occur almost exclusively at the sn-1- and sn-3-positions. The sn-1-position contained slightly more palmitic acid than the sn-3-position. The fatty acids with a chain length exceeding 18 carbons were preferentially incorporated in the sn-3-position. Linoleic acid was preferentially esterified at the sn-2-position, whereas oleic acid was equally distributed among the three positions. The amount of the saturated fatty acids, i.e., palmitic and stearic acid, and of oleic acid and linoleic acid incorporated in the sn-1-, sn-2-and sn-3-position, were each linearly related to their respective content in the triglycerides.

Metabolic changes in obese patients during fasting and refeeding.

SummarySixteen obese women and two obese men were submitted to total fasting. During the first seven days the mean cumulative weight loss amounted to 6.33 kg (range : 2.9 - H.o kg). This decrease in weight was mainly due to losses of body fluids. When refeeding some of the patients with different types of hypocaloric diets, it appeared that glucose administration curtailed abruptly urinary sodium excretion, causing fluid retention and eventually a gain in body weight and the development of edema. This effect on bodily hydration was not seen when giving proteins (casein) or fat (butter). A review of the literature concerning the influence of dietary constituents on body fluid balance is given. The possible mechanisms of the sodium-retaining action of carbohydrates are discussed.

Invloed Van Het Geslacht Op Het Corticoidenmetabolisme

SummaryCertain diseases occur more frequently in men than in women and vice-versa. Differences in hormonal pattern may explain in part this unevenly divided morbidity. The authors made a comparative screening of corticoid metabolism in both sexes using dosage methods of the group reaction type.The results obtained are to be divided in 3 categories. As far as corticoid production is concerned, men seem to have a greater maximal capacity to produce corticoids than women. This difference occurs independently of differences in apparent distribution volume (A.D.V.) between the two sexes.Cortisol is removed more rapidly from the bloodstream in man as in women. Furthermore, studies of the Reddy/Appleby ratio seem to indicate there are also qualitative differences in corticoid metabolism between the two sexes.The authors devised a stress of the first-experience type who did give a significant elevation in fluorimetrically determined plasmacorticoids in men but not in women. This elevation did disappear in the age...